It’s y=3x-3 that is where the line passes thru
On your papers does it say what x equals?
X + y = 4200 so x = 4200 - y
0.035x + 0.045y = 174
substitute x = 4200 - y into 0.035x + 0.045y = 174
0.035x + 0.045y = 174
0.035(4200 - y) + 0.045y = 174
147 - 0.035y + 0.045y = 174
0.01y = 27
y = 2700
x + y = 4200
x = 4200 - 2700
x = 1500
answer
$1500 in <span>3.5%
$2700 in 4.5%</span>